For the purposes of this description, a glazing verge of a glass pane will be understood to be the outwardly-facing margins of a glass pane adjoining the peripheral edge along the broad faces of the pane and the narrow edge face thereof between the broad surfaces. In the case of a glass pane consisting of two glass sheets, i.e. double-glazing, it is the margins of the outer broad faces adjoining the peripheral edges of two glass sheets, the narrow edge faces thereof and the seal between the sheets, i.e. the span between these faces along the narrow sides of the double glazing. Stated otherwise, a glass pane consisting of a single glass sheet has a pair of broad faces adjoining a narrow edge face extending around the periphery. The glazing verge is then defined as this narrow edge face and the margins of the broad faces adjoining the narrow edge face extending around the periphery of a width of the order of the width of the narrow edge face or somewhat greater.
This term is used because it describes the portion of the pane which in glazing is held within the frame in common parlance, and is intended to avoid confusion with terms such as "edge" and "rim" or "corner" which may refer to the sharp junction between faces of the glass pane. Further ramifications of the glazing verge will be described below.
In the prior art fire-resistant structural component described in German Patent document DE 30 44 718 A1, a glazing verge of the glass pane is provided on both of the broad surfaces, i.e. on the margins described above, with a coating of a heat-conductive material. The heat-conductive coating is received in a glazing groove of a frame with an intervening heat-insulating barrier material which can be composed of a fibrous filler.
This construction has been found to be effective as long as the thermal stress on the structure in the case of fire is not excessive and the fire-resistant duration is not expected to be high. To improve the fire-resistance duration, the coating can be extended beyond the free edges of the receiving groove and thus can project inwardly of the frame beyond the heat-insulating filler. However, the combination of the insulation and the frame or coating construction and the thinness of the coating appear to make the assembly incapable of withstanding high thermal stresses and more severe fire conditions.